Determination of carbohydrates by liquid chromatography: lactose in milk

A rapid, simple method for the determination of lactose in milk or milk products is described. An internal standard (galactose) is added to the milk which is then extracted with carbon tetrachloride. A sample of the aqueous layer is injected onto a strongly acidic cation exchange column (Li⁺ form, 17 μm particles) and eluted with aqueous ethanol, the eluent composition being monitored with a modified moving-wire detector. Applications demonstrating the precision and accuracy of the method are described.     

Making computational sense of Montague's intensional logic

Montague's difficult notation and complex model theory have tended to obscure potential insights for the computer scientist studying Natural Language. Despite his strict insistence on an abstract model-theoretic interpretation for his formalism, we feel that Montague's work can be related to procedural semantics in a fairly direct way. A simplified version of Montague's formalism is presented, and its key concepts are explicated in terms of computational analogues. Several examples are presented within Montague's formalism but with a view toward developing a procedural interpretation. We provide a natural translation from intensional logic into lisp. This allows one to express the composition of meaning in much the way Montague does, using subtle patterns of functional application to distribute the meanings of individual words throughout a sentence. The paper discusses some of the insights this research has yielded on knowledge representation and suggests some new ways of looking at intensionality, context, and expectation.     

Alkaloids and procyanidins of an Uncaria sp. from Peru

The direct and indirect effects of staphylococcal enterotoxins A and C on the flux of water, sodium, and potassium have been studied in paired Thiry Vella fistulae in dogs. Administration of toxin resulted in a significant decrease in absorption, both in the loop to which the toxin had been administered and its pair. This decrease in absorption was associated with a decrease in movement out of the lumen, movement into the lumen remaining relatively unchanged. The mechanism of action of staphylococcal enterotoxins is discussed, and comparisons made with other enterotoxins.     

Automatic collector of expired 14CO2 for liquid scintillation counting

A filtration technique was employed to trap 14CO2 continuously for liquid scintillation counting. Devices for delivering scintillator and ethanolamine solutions were combined symmetrically with two fritted-glass aspirators for alternating operation. The collector was regulated by a fraction collector timer. Trial and animal tests indicated that the described method was efficient, reliable, and more convenient for frequent collection over long periods than alternative methods. The automatic collector was used for metabolic studies of [1-14C] arachidonic acid in rats kept in metabolic cages and the results were processed by multicompartmental analysis.     

The fatigue of structural wire strands

This paper presents the results of a limited series of large scale in-line and bending fatigue tests on socketed structural strands typical of those used as stays for guyed masts and for suspension bridge hangers. The strand, consisting of a group of hard drawn galvanized steel wires laid up helically about a common axis, is terminated by zinc filled conical sockets. The various failure mechanisms, concentrated on the wires close to the socket, are described and discussed. It is concluded that conservative predictions of the in-line fatigue lives of real strands should be possible although further work is needed on bending fatigue.     

State laws mandating mental health insurance coverage

Insurance companies and administrators of group insurance plans have accepted the premise that coverage for mental illness must be different from coverage for other health problems, and thus insurers continue to limit their liability through various exclusions and restrictions. For several years providers and consumers of services have worked for the enactment of state laws that mandate or regulate certain kinds of coverage for mental illness; as of January 1, 1977, a total of 22 states had such statutes. The author presents a state-by-state summary of the provisions. He also classifies many of the provisions into six categories and discusses the probable basis for their enactment.     

Statement on mental illness and mental retardation.

The statement made on behalf of the American Psychological Association is in support of Senate Bills 755 and 756 developed by Congress in response to President Kennedy's message on mental illness and mental retardation. "The psychologist is vitually concerned with the problems of mental disorders and of mental retardation. He is especially interested in research, and in the provision of services to people through the organized agencies of society, such as the public schools, community mental health centers, hospitals, institutions for the retarded, and rehabilitation agencies of many kinds." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biosynthesis of mitochondrial DNA. Is 8 S DNA an artifact?

Sucrose density gradient fractionation of isolated rat liver mitochondrial DNA ordinarily yields two peaks, one at 39 S, the other at 27 S. However, when these mitochondria are first incubated with a labeled DNA precursor, a labeled peak at about 8 S is also observed. Is this low molecular weight 8 S DNA merely an artifact of contamination or breakdown, or is it a functioning part of the mitochondrial genome? That it is not a nuclear contaminant is shown by: (a) the absence of nuclei or nuclear fragments in active mitochondrial preparations; (b) the insensitivity of 8 S DNA synthesis to treatment of mitochondria with DNase and RNase; (c) the ability of inner membrane preparations to synthesize this DNA; (d) the ability of atractyloside to inhibit incorporation of [3H]dATP into 8 S and 39 S or 27 S DNA equally; (e) the labeling of 8 S DNA (as well as 39 S and 27 S DNA) but not of nuclear DNA after the administration in vivo of [3H]thymidine. The evidence that 8 S DNA is not an artifact resulting from DNA breakdown during mitochondrial incubation or DNA isolation is as follows: (a) 8 S DNA can be isolated from unincubated mitochondrial; (b) 8 S DNA becomes labeled when labeled DNA precursors are administered in vivo; (c) 8 S DNA biosynthesis continues in the complete absence of labeled 39 S or 27 S DNA (whose synthesis is repressed by ethidium bromide), making it unlikely that 8 S DNA is formed from the breakdown of 39 S or 27 S DNA; (d) substitution of milder methods of DNA extraction does not decrease 8 S DNA labeling; moreover, the usual conditions of extraction, when applied to purified 39 S and 27 S DNA, do not generate 8 S DNA, nor does an additional mitochondrial washing cycle; (e) the specific radioactivity of 8 S DNA is higher than that of 39 S or 27 S DNA, making it improbable that the latter forms are precursors of 8 S DNA. Since 8 S DNA is double-stranded, it is not identical to the 7 S fragment of D loop DNA. The hypothesis that the artifactual nicking of those DNA molecules which contain opposing D loops leads to the release of double-stranded fragments was tested. The DNA which was released was predominantly (and probably completely) single-stranded. We conclude that 8 S DNA is probably not an artifact and studies are in progress on its function.